The present invention relates to railway coupler connections and more particularly to an improved draft key bearing arrangement for a slackless coupler member in which the longitudinal draft loads of the coupler member are substantially eliminated from the sill side castings of the draft key bearing arrangement allowing for external attachment and easy removal of the sill side castings.
Railway cars are connected together by coupler members, namely drawbars or couplers. Drawbars are integral units known to be used in the railroad industry to extend between and permanently connect two or more railway cars. Couplers are independent units on each car which interconnect with one another, between adjacent cars, to form a connection. In either instance, a shank end of the drawbar or coupler extends into the center sill of a railway car where it is secured to transmit longitudinal loads to the car.
One type of drawbar is currently positioned and held within the center sill of a railway car by the combination of a draft key inserted through a pair of sill side castings. Such an arrangement is shown in Altherr et al., U.S. Pat. No. 4,700,853 wherein the sill side castings have inward projections to center the drawbar within the center sill. In addition to laterally positioning and holding the drawbar, the sill side castings have also fully encircled the draft key so as to transfer the longitudinal loads, particularly the draft load, of the drawbar from the draft key to the center sill. A direct transfer of the longitudinal loads from the draft key to the center sill has not been practical as the center sill side walls do not have the cross-sectional area necessary to accept these loads from the draft key without fatigue or failure.
It is advantageous to railroad owners to have railway cars which can be converted from a drawbar arrangement to a coupler arrangement. However, the inward projections of the sill side castings are not compatible with coupler shanks. Furthermore, these sill side castings are subject to in-service wear and must therefore be replaced. This makes removal of the sill side castings desirable.
However, it has heretofore been necessary that the sill side castings be rigidly secured (heavily welded) to the inside of the center sill so as to withstand the longitudinal draft loads of the drawbar. Accordingly, the only way to remove the sill side castings has been to burn off the heavy welding on the inside of the center sill. Burning off this heavy weld is extremely difficult and often causes damage to a portion of the center sill side wall which must be restored or replaced. This procedure is costly and time consuming.